PRODUCTION OF 5-ARYLHYDANTION

摘要

PROBLEM TO BE SOLVED: To readily produce the subject high-purity compound by reacting a specific alkyl oxoacetate with urea and a specified aryl compound in the presence of an acid. SOLUTION: An alkyl 2-oxoacetate represented by formula I (R1 is an alkyl) is reacted with urea in an amount of preferably 1.0-3.0 mol based on 1 mol of the alkyl 2-oxoacetate and an aryl compound represented by formula II (R2 is hydroxyl or a lower alkoxy; and R3 and R4 are each H, hydroxy or the like) (preferably phenol) in an amount of preferably 1.0-2.0 mol based on 1 mol of the alkyl 2-oxoacetate preferably in the presence of a 1-10 N acid (preferably hydrochloric acid or sulfuric acid), preferably in an aqueous medium at 60-95 deg.C to thereby produce the objective compound represented by formula III. The compound represented by formula I in a required amount may previously be added to a solution containing the urea and the compound represented by formula II or slowly added to the reactional system. The objective compound may be isolated by cooling the reactional liquid and carrying out the solid-liquid separation.